Method of distilling coal



Dec. 5, 1933. H. STEVENS METHOD OF DISTILLING COAL Filed OC'b. 18, 1930 INVENTOR.

ZM ATTORNEYS.

Patented Dec. 5, 1933 PATENT. OFFICE LIETHOD OF DISTILLING GOAL Harold Stevens, Cincinnati, Ohio, assignor, by mesne assignments, to Harold Stevens, trustee Application October 18, 1930. Serial No. 489,536

7 Claims.

This invention relates to a method of distilling vapors and gases from coal, and leaving residual. The nature, objects and advantages of the invention will be best understood from the following:

In carrying out my invention I charge a relatively large quantity of coal into an upright retort of such configuration that the charge assumesthe shape of an elongated column, for all m practical purposes filling the retort. I supply heat by means of an electric current, to which end I immerse resistor means, such, for example, as one or more starting fuses extending lengthwise of. the retort and composed of coke or other suitable material. The resistor means is supported in electrodes and is adapted to be centrally embedded in the column of coal when the charge is introduced. I

The current is passed through the starting fuse, the fuse becomes hot and heats the con,-

tiguous coal, converting it into coke. This coke now becomes part of the path for the current so that, in effect, the diameter of the resistor increases. Thus the coal, as it is progressively coked radially outward, becomes part .of the resistor and heats the adjacent, coal. The application of current may be continued until all of the coal has been coked, but I prefer to cut off the current at a predetermined point, al-

- 3o lowing the remainder of the coal to be coked by the heat of that which has already been coked.

It is of importance to control the current, and

for this purpose I employ a multiple-tap trans- 35.former if alternating current is used and a motor generator set if direct current is used.

The control of the current is dependent, of

course, upon the particular method of operation, the change in the size of the core constituting the resistor and other operating conditions. For example, I contemplate controlling the current to correspond with the increase of the diameter of the resistor element.

In addition to this control I find it very advantageous to impose an additional control by means of which the temperature of the charge may be regulated to secure the highest or any given quality of gas on the basis of heat units per unit of volume.

In other words, the first control mentioned is one which is more calculated to affect operation, whereas the latter control affects quality of gas.

I accomplish the foregoing by means of the method and apparatus disclosed in the accompanying drawing, wherein The figure is a vertical section through a preferred form of apparatus useful in carrying out the process. a

Referring now to the drawing, the reference numeral 7 indicates the retort which is preferably of the construction shown and described in my copending application Serial No. 489,535, filed October 18, 1930.. The retort has a refractory lining 8,.a metallic shell 9, and an intermediate filling 10 of dense material, such as cement, or the like, acting as a barrier to liquid products of distillation. The retort has a door 11 at the bottom for coke discharge and is provided with means at the top (not shown) for introducing the charge.

The starting fuse or resistor is shown at 12 and the high potential electrode at 13, and the low potential electrode at 14. The transformer is indicated at 15. a

In operation the resistor is placed in position preferably by introduction through the hollow electrode 13 and then the charge is introduced and the current turned on and regulated as -required, the coking operation proceeding as hereinbefore described.

To control the temperature of the charge in order to govern the quality of gas obtained, I introduce steam preferably at a plurality of points lengthwise of the retort through suitable pipes 16 which may be controlled by valves such as indicated at 16a. The regulated introduction of steam enables me to obtain temperature control lengthwise of the retort with any desired modification of the quality of the gas generated as may be desired.

The liquid products of distillation drain off at 1'7 and the gases are'preferably drawn off at the bottom through the conduit 18. If desired it may be drawn off at different points lengthwise of the retort as indicated at 19 which may be controlled by valves such,as indicated at 1901. As an additional means to secure uni-' formity in product, I may provide in the charge, at spaced intervals, horizontal layers 20 of material such as coke and these layers, therefore, have approximately the same unit resistance asthe coal after treatment thereof. These tend to prevent the formation of any continuous tarry wall and minimize the liability of gases passing through regions of higher temperature than that at which the gases were liberated, thus obviatingdegradation. Where these layers are employed, I prefer to introduce steam in each intel-mediate section of coal and I also prefer to locate the gas offtakes 19 opposite such layers.

dblown through an incandescent bed of coke.

Here the gas is essentially one which is derived from the distillation of the coal and the quality of that gas is governed by the regulated admission of steam or its equivalent.

Attention is called to the fact that various features herein disclosed are described and claimed in one or more of the following of my copending applications: Serial No. 489,530, filed October is, 1930; Serial No. 439,532, filed October 18, 1930; Serial No. 489,534, filed October 18, 1930; and Serial No. 489,535, filed October 1S, 1930.

ll claimzl. The process of distilling vapors and gases from coal and leaving coke, which comprises -ging the coal into a substantially vertical retort so that the coal takes the form of a .1: about a substantially vertical and generally centrally located resistor element extending therethrough, heating the charge by passing an electric current through the resistor and progressively through the progressively coked portions of the coal surrounding the resistor, and controlling the heating current to correspond with the increase of the diameter of the efiective resistor as additional portions of the coal are progressively coked.

3. A process for distilling vapors and gases from coal and leaving coke in a vertically elongated retort, which includes charging the coal into'said retort in horizontal layers and positioning a layer of solid vapor-pervious and current conducting material between said layers of coal, said material being substantially unafiected chemically or physically by the distillation temperature, providing a resistance path for an electrical heating current throughout the height jacent portions of the coal which have been coked and through said layer of material originally positioned. between the layers of coal throughout the elongated dimension of the retort, and withdrawing the gases and vapors liberated in a central region of the charged retort 'radially outwardly from said central region through said layer of vapor-pervious material originally introduced as the treatment proceeds.

a. A process for distilling vapors and gases from coal and leaving coke in a vertically elongated retort, which includes charging the coal into said retort in horizontal layers and positioning a layer of solid vapor=pervious and current jacent portions of the layers of coal within the retort and to coke the same, passing an electrical heating current through said annularly adjacent portions of the coal which have been coked and through said layer of material originally positioned between the layers of coal throughout the elongated dimension of the re tort, whereby the gases and vapors liberated in a central region of the charged retort may pass radially outwardly from said central region through said layer of vapor-pervious material originally introduced as the distillation proceeds, and withdrawing vapors and gases from the retort through an upright side wall thereof at a point substantially in the horizontal plane of the layer of vapor-pervious material originally introduced.

5. A process for distilling vapors and gases from coal and leaving coke in'a vertically elongated retort, which includes charging the coal into said retort in horizontal layers and positioning a layer of solid vapor-pervious and current conducting material between said layers of coal, said material being substantially unafiected chemically or physically by the distillation temperature, providing a resistance path for an electrical heating current throughout the height of the retort substantially centr thereof, passing an electrical heating current through the resistance path whereby to heat annularly adjacent portions of the layers of coal within the retort and to coke the same, passing an electrical heating current through said annularly adjacent portions of the coal which have been coked and through said layer of vaporpervious material originally positioned between the layers of coal throughout the elongated dimension of the retort, whereby the gases and vapors liberated in a central region of the charged retort may pass radially outwardly from said central region through said layer of vaporpervious material originally introduced as the treatment proceeds, and introducing steam into the retort to control the temperature of the coal therein.

6. A process for distilling. vapors and gases from coal and leaving coke in a vertically elongated retort, which includes charging the coal into said retort in horizontal layers and positioning a layer of solid vapor-pervious and cur= rent conducting material between said layers of coal, said material being substantially un- I aflected chemically or physically by the distillation temperature, providing a resistance path for an electrical heating current through= out the height of the retort substantially centrally thereof, passing an electrical heating current through the resistance path whereby to heat annularly adjacent portions of the layers of coal within theretort and to coke the same, passing an electrical heating. current through said annularly adjacent portions of the coal which have been coked and through said layer of vapor-pervious material originally positioned between the layers of coal throughout the elongated dimension of the retort, whereby the gases and vapors liberated in a central region of the charged retort may pass radially outwardly from said central region through said layer of vaporpervious material originally introduced as the treatment proceeds, and introducing steam into the retort through an upright side wall thereof at a point substantially in 'the horizontal plane of a layer of coal to control the temperature of the coal.

7. The process of coking coal in an elongated retort, which includes charging coal into the retort in layers lying in planes transverse the long dimension of the retort, interposing a layer of coke of approximately the same unit resistangle as that of the coke to be produced, providing a resistance path for an electrical heating current throughout the length of the retort substantially centrally thereof, passing an electrical heating current through the resistance path whereby to heat annularly adjacent portions of the layers 01' coal within the retort and to coke the same, passing an electrical heating current through said annularly adjacent portions of the coal which have been edited and through the layer or vapor-pervious material originally positioned between the layers of the coal throughout the elongated dimension of the retort, and withdrawing the gases and vapors liberated in a central region of the charged retort radially outwardly from said central region through the vapor-pervious layer of coke originally introduced as the treatment proceeds.

HAROLD STEVENS.

CERTIFICATE OF CORRECTION,

iiatent No. l, 938, 124.

December 5, 1933;

HAROLD STEVENS.

it is hereby certified that error appears correction as and that the said Letters Patent should be read above numbered patent requiring "residual" insert the word coke;

with this correction therein that the same may conform in the Patent Office.

Signed and sealed this 9th day oi ianuary,

($cal) in the printed specification of the follows: Page 1, line 2, after to the record of the case 1*. M. Hopkins Acting Commissioner of Patents 

